This invention relates to a log structure for prefabricated log sections suitable for constructing log buildings.
In the construction of log buildings, prefabricated log sections are laid in a superposed manner to form walls. Commonly, complementary matching upper and lower longitudinal surface structures are provided on the log sections so that when the log sections are placed longitudinally and horizontally one on top of the other, the matching surface structures interfit with one another to join the log sections together. One form of such matching surface is provided by the formation of matching or complementary tongue-and-groove on the upper and lower surfaces of the log sections. The tongue-and-groove structure comprises a tongue extending the entire length of the log section and being formed on the upper surface therein, and a groove also extending the entire length of the log section and being formed in the lower surface therein. The tongue and the groove are dimensioned to interfit with each other snugly. However, such tongue-and-groove structure usually does not provide satisfactory joints between the log sections. This is primarily due to the difficulty in precisely forming the elongated tongue-and-groove on such relatively large structures. Therefore, often large gaps are present in the joints. This is further worsened by the tendency of the tongue to crack under changing weather conditions. Thus, air, vapour and moisture can pass through the joints formed by such interfitting surface structure. Normally, in order to eliminate such air and vapour leakages, a sealing material such as caulking compound is placed on the outside of the joints. The sealing material although eliminating the leakages, inherently destroys the aesthetic appearance of the wall and the log building as a whole. Furthermore, the sealing material often falls off easily from the joints due to the continual expansion and contraction of the log sections under changing weather conditions and the ossification of the sealing material due to prolonged exposure to the atmosphere.
In order to obviate the above problems, attempts have been made to place the sealing material within the joints. However, in order to achieve this the surface structure of the log sections is usually very complicated and the log sections are difficult and expensive to manufacture and time consuming to install.
Also, commonly the end-to-end joints between the log sections are formed by simply abutting the end surfaces of the log sections together and filling the joints with a sealing compound. Sometimes, complementary end structures are provided in the log sections to form scarf end joints between the sections. Again, due to the natural contraction and expansion of the log sections, such common end-to-end joints are far from satisfactory.